Phonograph reproducer



April 30, 1929. mso 1,711,265

PHONOGRAPH REPRODUCER Filed Feb. 10, 1926 lNVENTOfi BY 42x41 ATTORNEY Patented Apr. 30, 1929.

UNITED STATES PATENT or'rlcrz.

THOMAS A. EDISON, OF LLEXVELLYN PARK, WEST ORANGE, NEW ASSIGNOR TO THOMAS A. EDISON, INCORPORATED, OF WEST ORANGE, JERSEY, A COR- PORATION OF NEW JERSEY.

PHONOGRAPH REPRODUCER.

Application filed February 10, 1926. Serial No. 87,200.

My invention relates to phonograph reproducers and particularly to those of the type adapted for use with disc records having vertically undulating grooves and in which the stylus is carried by a lever mounted on a floating weight, said lever being connected to a diaphragm mounted me sound box; it

tained under more tension so that it will have I a potentially greater amplitude ofvlbration,

due to the resulting increased potential energy' thereof, and accordingly will cause the stylus in trachingthe record roove, to follow and be maintained in close engagement with the bottoms of all the deep undulations of such groove as well those of theshallow undulations. i

Another object of my invention is to provide a reprodiwer of the character above described, wherein thediaphragm is placed under greater tension to obtain the desired in-I creased volume, by removnig a part of the pressure of the stylus on the record due to the action of the floating weight and transferring it to the diaphragm.

Further objects of my invention are to provide a reproducer of the typedescribedwith means whereby the diaphragm will beprevented from becoming permanently set in a deformed shape because of the increased 7 stress to which the same is subjected in order to n'iaintain the same under a greater tension,

and to provide an improved connection beother than in the direction of itslength.

tween the stylus lever and the diaphragm which will not stretch in the continued use of the reproducer and which has noc tendency, in the operation of the reproducer, to vibrate impairing the quality Other objects and features of my inventlon will be hereinafter more fully described and claimed. I

In order that my invention may be more clearly understood, attention is directed to the drawing accompanying and forming a' part of this specification,'and in which:

Fig. 1 is a side elevation, partly in section,-

of a reproducer embodying a preferred form of my inventlon p y 1* 1g. 2 1s a front elevation showing a detail of construction of the reproducer shown in Fig. 1.; and

Fig. 3 is a greatly enlarged fragmental sectional view of the connection employed between the stylus lever and the, diaphragm of the reproducer shown in Fig. 1.

Referring to the drawing, and especiallyto Fig. 1, the reproducer shownis of the Edison type and comprises the usualcup 1,having a sound chamber 2 which is circular in cross-'- The cup 1 is provided centrally section. thereof with an upstanding neck 3 to which is suitably secured at the smaller end thereof the usual tapering sound conducting-tube 4, said tube 4; being adapted to be connected at its larger end to the small end of the usual horn or sound amplifier of the phonogra 'ih.

Reference. character 5 represents the dia phragm of the rcproducer, this diaplnagm, as shown, being of the form usually employed in Edison reproducers and consisting of a number of superposed layers of Japan-esericc papersuitablv secured together. ecured to the lower face of the diaphragm 5 by shel lac or other suitable means is ajcenter nece 6 of cork or similar material which is comparatively thick at the center,- tapers off towards its edge and covers a'large portion of the area of the diaphragm.v The curvature'of the outer surface. of the cork center piece 6 should be such that substant ally the whole body portion of the diaphragm flexes into a spherical shape when stresses are transmitted thereto through the stylus lever and the connections between the. latter and the diaphragm. An ivory button .7 is cemented or otherwise secured to the center of the upper face of the diaphragm 5. .The s ound'chain' her 2 is provided with a seat for: the diaphragm 5 against which the l'atter'is held at its edge portion between two annular pack ing rings or gaskets 8, 8, by means of a clampring 9 screwed into the cup. A thin smooth metal ring 10 is disposed between the lower gasket 8 and the clamping ring 9 to prevent deformation of such gasket upon turningmovement of the clamping ring when the latter tightened.

The reproducer c 1p 1 is provided with a rearward extension 11, and a floating weight 12 is pivotally connects l to this extension for movement about a vGl'tlCdl axis by means comprising a piv' t block 13, a pivot pin 1 1 secured at its lower end to this block and rotatablymounted in a vertical opening in the end of the extension 1.1. and a screw 15 threaded into the upper end of the pin 141, the floating weight beine' supported from the block 18 by means of a hat spring 16, one end of which is secured to the block and the other end of which is suitably secured to the adjacent end of the floating weight. A stylus lever 17 is pivotally supported on a horizontal'pin 10 which is fixedly mounted at its ends in spaced bearings 19, (only one of which is shown) projecting downwardly from the lower surface of the floating wei ht 12 adjacent the forward end of the latter. The stylus lever 17 has a reproducing stylus 20 secured in and extending from one end thereof and has its other end secured to the button 7 at the center of the diaphragm 5 by means comprising a link 21 extending vertically through an opening 22 in the floating weight. The usual limit pin 23 is secured to the forward end of the floatingweight 12, this pin extending within a loop 2 1 secured to the under side of the reproducer' cup 1 and co-acting with such loop to limit the vertical and lateral movements of the floating weight with respect to the reproducer cup.

The link 21 is loosely connected'at its lower end to the stylus lever 17 as by means of an eye loosely engaged with a notch or slot 26 in the end of the stylus lever and having a hollow extension 27 within which the said lower end of the link 21 is fixed. The upper end of the link 21 is connected to the button 7 ot the diaphragm by a member having a lower recessed end portion 28 within which the upper end of the link is fixed and an upper threaded end portion 29 extending through. an opening in the button 7, and a nut 30 threaded on said portion 29. The member to which the upper end of the link 21 is connected is provided. intermediate the portions 28 and 29 thereof with a flange or collar. 31 having an upper conical face or surface. The diaphragm 5 and the cork piece 6 are provided with central registering openings within which the upper end of the link 21 and. the portion 28 of the member to. which the same is secured are disposed, and the button 7 is provided on its under side with a recess registering with the said openings in the diaphragm and cork piece 6 and having a conical end wall providing a for the upper conical face of the collar 31. Upon tightening the nut 30 the collar 31 is brought to aposition with the conial face thereof in firm, close engagement with the said conical end wall of the recess in the button 7 and the upper end of the link 21 is thus firmly and rigidly cured to the button 7 and the diaphragm 5.

i'l hen a reproducer of substantially the same construction as that thus far described is in normal operating position with the stylus thereof engaging the groove of the record being reproduced, the floating weight maintained by such en 'agement in a position with the limit pin extendg from the forward end thereof occupying a substantially central position within the limit loop depending from the reproducer cup, and the diaphragm is subjected to a certain amount of stress and therefore placed under so 'ie tension by the action of the floating weight.

I have found that if the diaphragm of a reproducer is subjected to stress in addition to that to which it is ordinarily subjected when the stylus is in operative engagement with a record, so that such diaphragm is maintained under an increased tension, the potential amplitude of vibration of the diaphragm will be greatly increased and the volume of reproduction obtained greatly augmented due, in

part at least, to the fact that under these con ditions the elasticity of the diaphragm will act to force the stylus to the extreme low points of the deepest undulations in the record groove and thereby effect the reproduction of pracically all sounds recorded. One of the principal improvements contemplated by my invention is the provision of means, whereby such additional stress is imposed on the diaphra gm of a reproducer. The ineans'which employ for this purpose in the reproducer of the particular construction shown and described preferably attains the desired result by relieving or removing a part of the PIGS.

sure of the stylus on the record due to the action oi the floating weight and transferring it to the diaphragm, and this means preferably comprises a retractile spring 32, one end of which is connected as by means of an eye to the-floating weight 12, and the other end of which. is connected as by means of an eye 3% to the stylus lever 17 at a point directly ab ve the stylus 20. The spring preferably has quite a number of turns or coils and is preferably disposed in a vertical position with the.

main body portion thereof disposed within a recess 35 provided in the floating weight 12 between the opening 21 therein the forward end "thereof. The construction and in rangement are such that the spring 32 will be in an extended condition v. lien the reproducer is in playing or operative position with the stylus 20-engaging the record it, as illustrated in Fig. 1, and consequently will act to impose additional stress on the diaphragm and thereby place the latter under increased ten suits from the action of the spring 32 in transferring part-off the pressure of the stylus on the record, due to the action of the floatingweight, to the diaphragm. It will therefore be apparent that besides imposing additional stress on the diaphragm, the spring 32 also tends to lessen or decrease the pressure with which the stylus engages the record under the action of the floating weight 12, and con sequently that with the use of this spring, other things being equal, the wear on the record due to the engagement of the stylus therewith is materially decreased, or that the inertia of the floating weight or other movable part or parts between tie stylus and diaphragm may be inateriall increased, as is son'ietimes desirable, without any increase of the normal pressure of the stylus on the rec- 0rd. v

In reproducers oi: this type as ordinarily constructed, that is, when provided with no means such as described-for imposing stress on the diaphragm in. additionto that due to the action of the fioatii a weight, the stress on the diaphragm is entirely relieved when the reproducer is in inoperative position with the limit pin resting on the bottom of the When, however, the reproducer V means between the stylus lever and the d1alimit loop.

is provided with the retractile spring 32 gged as described, or other equivalent means, the stress on the diaphragm is continuous and, in the absence of any comp-en-' ng means, is not relieved when the reprodueer is in such inoperative position, but This 18 due moves 1? a posit-ion in which the limit pin rests on the bottom the loop 2%, the spri o 2315 will be sf further extended or stretched and ereby impose still more strcss on the dia- :i'a; 1n1 5. stress when the reproduceris moved to inoperative position, I preferably provide a second spring 36, or other equivalent means, which is secured at onoend to a horizontal pin. 31 mounted within the neck 3 of the reproducer cup and at its other end to the dia ii-liragpn by means of a hook formed on its lower end engaging with an eye provided in ension'ZZO of the nut which constithat the spring 36 is only very slightly stretched or extended when the-reproducer is in operative position, as shown in Fig. 1', and then exerts but very little pull on the dialo compensate for this extra t part of the means for connecting the MPEG1 end of the link 21 to the d1aphragm 5. The snrmgBS which is alsoa retr-actile has but very few turns or coils as red with the spring 32 and acts in a; .ion contrary to the latter,'the construction and'arrangement preferably beingsuch phragm. If made of certainmaterials and subjected to too great and continuous stresses, the diaphragm is likely, particularly in hot or humid climates, to dish and set in a deformed shape, especially when the repro ducer isin inoperative position for a considerable period of time. The retractile spring 86 overcomes this tendency of the diaphragm to set in a dished shape, for while it is not sufiiciently tensioned to exert enough force or pull to relieve the diaphragm of the additional stress which the spring 32 imposes thereon when the reproducer is in operative position, the said spring 86 will exert a much greater effective upward pull on the diaphragmwhen the reproducer is moved to inoperative position as the slight extension of this spring result-mg i'rom' such movement of the reproducer, will, because of the comparaphragm whereby the vibrations transmitted to the diaphragm will exactly correspond to those of the stylus 20 in trackingthe record groove. If connecting means such as has heretofore been used are employed betvi een the stylus lever and the diaphragm, I find that the quality of the reproduction is inn paired, when the diaphraginis maintained under increased tension as described herein,

due in part atleast,to the fact that side vibrations are set up in such connecting means in the operation of the reproduccrf I have found. however that a reproduction may be obtained which is unimpaired in quality by the use or an improved connection between the stylus lover or arm and the diaphragm which is practically dead and has no tendency to vibrate. A preferred form of such a con? nection comprises a flexible connecting link 21 formed ofa piece of fish snell, or the-like, preferably consisting'or" a central body or core made up of a number of silk strands covered, withl'fine copper wire lO'closely and tightly wound thereon. A. connecting link 21 composed of a piece of smell such as described is dead, it has no natural tendency to vibrate, it doesnot stretch under the vigorous'vibrations imparted to it by the undulations ot' the record groovethrough the stylus 20 and lever 17, and: it has no tendency whatever to vibrate sideway'sduring the operation 0t thereproducer. Consequently, where such connection is employed between the stylus lever and the diaphragi'n, the only vibrations produced in such connection will. be endwise vibrations corresponding to those iu'iparted theretoby the stylus 20 through the lever .17, and conscqueu ly the vibrations trai'ismitted to the diaphragm 5 will correspond iil'lttttl with those oi the stylus A0 in tracking the record groove and a faithful rej'iroduction will be obtained. Moreover a flexible link of this character enables a reproduction of unimpaired qua ity to be obtained, even when the di a ,-..-h ragm is subjected to e tra stress as described, with a const-ru tion. wherein the link is attached to the diaphragm and the stylus arm or lover by a rigid or fixer crmnection at one end. and bv a loose conncction at its other end.

It is to be understood that the construction speciiiailly shown and described herein is merely illustrative oi? my invention and that such construction is ubject to various changes and modifications without departure from the spirit of my invention or the scope of the appr-znded claims.

Havin now described n'iy invent-ion, what i. claim as new and desire to protect by Letters Patent is as follows: 7

1. in a reproducer, a diaphra '1, a member connected to said diapl'iragiu and carrying a stylus, means wl'iereby when. the reproducer is in operative position the stylus adapted to be maintained. in engagement under pressure with a record, and means-adapted t subject said diaphragm to stress in addition to stresses to which the same may be subjected by reason of such engagement of the stylus with the record, substantially as described.

2. In a reproducer, a diaphragm, a memw connected to said diaphragm and Carrystylus, means whereby when the reproducer is in operative position the stylus is :ulapted to be nmintained in engagement under pressure with a record, and. resilient n'ieans arrai'iged to impose stress on said diaphragm in addition to stresses which they be imposed thereon by reason of such r-mgageroent ot the styl s with the record, substantially as described.

3. In a reproducer, a diaphragm, a member connected to said diaphragm and carrying a stylus,moans whereby when the reproducer is in operative position the stylus is adapted to be maintained in enga ment under press sure with a record, and means adapted to relieve or remove some of said pressure and transfer the same to the diaphragm to thereby place the latter under increased tension, substantially as described.

4:. In a reproducer, a diaphragm, a member iected to said diaphragm and carrying a I us, means whereby when the reproducer inoperative position the stylus is adapted to be maintained in engagement under pressure with a record, means adapted to subject said diaphragm to stress in addition to stresses to which the same may be subjected by reason of such engagement of the stylus with the record, and means for relieving the dia phragu'i oi at least a part of such additional 1 s when the reproducer is in inoperative position, substantially as described.

5. The combination of a sound box having a diaphragm mounted therein, a floating weight, a stylus lever mounted on said weight and connected to said diapl r gm, and means arrangel hen the stylus is in operative engagen'ient with a record to impose stress on said diaphragm in addition to stresses imposed thereon by the action of the floating weight, subs in ally as described.

6. lhe combination of a sound box having a diaphragm mounted therein, a floating weight, a styli'as lever mounted on said weight and connec l to said diaphragm, and resil- L'i ient means adapted whenthe stylus is in operative engage w nt with a record to maintain the phrag". "er a tension greater than that due to the stresses imposed thereon by the action oi? the dentin weight, substantially described.

7. Tl e combination a sound box having a diap iragn'i mount id. therein, a floating weight, stylus lever mounted on said weight and connected to said diaphragm, and means coacting directly with the stylus lever adapted when the stylus is in operative engagement *ith record to impose stress on said dia-' phragm in addition to stresses imposed thereon by the action of the floating weight, substantially as described. 7

8. The combination of a sound box having a diaphragm mounted therein, a floating weight, a stylus lever mounted on said weight and connected I to said diaphragm, means a t J(.l cons "ly to impose stress on said ld ion to any stress to which ..1 1, ed by the action of the floating weight, and means for relieving the diaplu'agm of at least a part. of such additional. stress when the stylus is in inoperative position with respect to a record, substantially as described. V

S). The combination of a sound box having faphra 'm mounted. therein, a floating a stylus lever mounted on said weight and connected to .aid diaphragm, and a re tractile spring connected to said lever and s arranged as to be extended when the stylus is in operative relation to a record to thereby impose stress on said diaphragm in addition to the stress imposed thereon by the action of the floating weight, substantially as described. V

10. The combination of a sound box having a diaphragm mounted therein, a floating wei ht, a stylus lever mounted on said weight and connected to said diaphragm, means comprising a sprin acting through said stylus lll) lever to impose stress on the diaphragm, When the stylus is in both operative and inoperative relation to a record, in additlon to stresses imposed on the diaphragm by the action of the floating Weight, and means for relieving the diaphragm of at least a part of such additional stress When the stylus is in inoperative relation to the record, substantially as described.

, 11. The combination of a sound box having a diaphragm mounted therein a floating Wei ght, a stylus lever mounted on said Weight and connected to said diaphragm, and means adapted when the stylus is in operative relation to a record to transfer a part of the pressure of the stylus on the record due to the action of the floating Weight, to the diaphragm, substantially as described.

The combination of a sound box having a diaphragm mounted therein, a floating Weight, a stylus lever mounted on said Weight and connected to said diapragm, and means comprising a retractile spring connected at its ends to the floating Weight and the stylus lever adapted when the stylus in operative relation to a record to transfer a part of the pressure of the stylus on the record due to the action of the floating Weight, to the diaphragm, substantially as described.

13. The combination of a sound box having a diaphragm mounted therein, a floatin g Weight, a stylus levermounted on said Weight and connected to said diaphragm, means for imposing stress on the diaphragm, When the stylus is in both operative and inoperative relation to a record, in addition to stresses imposed on the diaphragn'i by thenction of the floating Weight, and m ans comprising a spring acting on thediaphragm to releive the latter of at least a part of such additional stress when the stylus is in inoperative relation to the record, substantially as described.

1s. The combination of a sound box having a diaphragm mounted'thcrein, a floating Weight, a stylus lever mounted on said Weight and connected to said diaphragm, means comprising a'spring having its ends'respectively connected to the floating Weight and the stylus lever and adapted to impose stress on the diaphragm, when the stylus is in both operative and inoperative relation to a record, in addition to stresses imposed on the diapl'uagm by the action of the floating Weight, and means comprising a spring acting on the diaphragm to relieve the latter of at least a part of such additional stress when the stylus inoperative relation to the record, sub- 'ially as described.

15. The combination of a sound box having a diaphragm mounted therein, a floating W@1 "l1'i3, a stylus lever mounted on said Weight and connected to said diaphragm, and a retractile spring having its ends respectively connected to the floating Weight and that end of the stylus lever 0 posite the end thereof connected to the diap ragm, substantially as described. g V

16. The combination ofv a sound box having a diaphragm mounted therein, a floating weight, a stylus lever mounted on said Weight and connected to said diaphragm, a retractile spring having its ends respectively connected to the floating Weight and that end of the stylus lever opposite the end thereof connected to the diaphragm, and a second spring arranged to act on the diaphragm in a direction contrary to the action thereon or said first mentioned spring, substantially as de scribed.

17 The combination of a sound box'having a diaphragm mounted therein, a floating Weight, a stylus lever mounted on said Weight and connected to said diaphragm, a retractile coiled spring having its ends respectively connectedto the floating Weight and that end of the stylus lever opposite the end thereof connected to the diaphragm, and a second retractile coiled spring having its ends respectively connected to the sound box and the dia phragm, said second spring being arranged to exert stress on the diaphragm in a direction opposite to the stress imposed therein by said first mentioned spring and having feWer turns or coils than the latter, substantially as described. o

18. The combination of a sound box having a diaphragm mounted therein, a floating Weight, a stylus lever mounted on said Weight, means connecting said lever and the diaphragm comprising a flexible member formed of a piece of fish snell, and means acting through said lever and connecting means adapted When the stylus is in operative relation to a record to impose stress on said diaphragm in addition to the stress imposed thereon by the action of the floating Weight, substantially as described. a

19. The combination of a sound box having a diaphragm mounted therein, afloating Weight, a stylus lever mounted on said Weight, means connecting said lever and the dlaphragm comprising a flexible member which is substantially dead and has no natural tendency to vibrate, andmeans acting ing member, and means connecting said member to the diaphragm comprising a flexible member formed of a piece of fish shell, substantially as described.

22. The combination of a sound box having a diaphragm mounted therein, a stylus carrying member, and means connecting said member to the diaphragm comprising a flexible member consisting of a core formed of silk strands and line Wire covering said core and closely Wound thereon, substantially as described.

23. The combination of a sound box having a vibratory member mounted therein, a stylus carrying member, and means connecting said members comprising a flexible element consisting of a Wire-wound core of fibrous material, said element having a iixed or rigid connection at one end thereof Withone oi? said members and a loose connection at the other end thereof With the other of said members, substantially as described.

24. The combination of a sound box having a diaphragm mounted therein, a stylus carrying member, and means connecting said member to the diaphragm con'iprising a flexible member consisting of a Wire-Wound core of fibrous material, said flexible member having a fixed connection at one end thereof with said diaphragm and a loose connection at the other end thereof with said stylus carrying member, substantially as described.

Means for connecting the diaphragm and stylus carrying member of a sound box structure comprising a flexible member consisting of a wireW-ound core of fibrous material, substantially as described.

26. Means for connecting the diaphragm and stylus carrying member of a sound box structure con'lprising a flexible member formed of a piece of lish snell, substantially as described.

27. Means for connecting the diaphragm and stylus carrying member of a sound box structure comprising a flexible member consisting of a core formed of sill: strands and line Wire covering said core and wound thereon, substantially as described.

This specification signed this 1st day of February, 1926.

' 'rrios. .a. nmson. 

